Steam-pressure gage



H. BATES.

Steam Gage.

No. 18,272. Patented Sept. 29, i857.

UNITED STATES PATENT OFFICE.

HENRY BATES, OF NEW LONDON, CONNECTICUT.

STEAM-PRESSURE GAGE.

Specification of Letters Patent No. 18,272, dated September 29, 1857.

To all whom it may concern:

Be it known that I, HENRY BATES, of New London, in New London county andState of Connecticut, have invented a new and useful Improvement in theSteam- Gage; and I do hereby declare that the following is a full andexact description thereof, reference being had to the accompanyingdrawings, making part of this specification.

The nature of my invention consist-s in the arrangementof the sector,with teeth on its side face and a radial bearing projection near itsaxis, on an axis which is at right angles to the shaft of the pinionthat actuates the pointer and in proper relation, for united action, tosaid pinion, and to a controlling stud I, which terminates in aneccentric curve, as hereinafter specified. By this arrangement, thenecessity of employing a spring to return the sector and pointer totheir original or starting positions, when pressure is withdrawn isavoided, as the sector returns by its own gravity. Another advantage isalso secured, to wit, a compensation is provided for the decreasingspecific action of the sector on the pointer .under increased pressure,as" the bearing projection changes its point of bearing, and therebylengthens the leverage and increases the movement of the dialsimultaneously and correspondingly with the increase of pressure ofsteam, and the decrease in movement of the disk, and thus allinaccuracies which arise from the disk not yielding equally inproportion to the different degrees of pressure, but requiring, as thepres sure increases, a greater amount of additional pressure, owing toits capability of being extended, to produce a movement of the pointerto a position which will tell the true pressure of the steam.

Figure 1 represents a vertical section of the improved gageperpendicular to its face. Fig. 2 is a front view without the graduatedface and index. Fig. 3 is a front view with the face and index.

A A A Fig. 1 is a disk like form or case made of cast iron to which thedifferent parts are attached. B, B, is a ring of the same material.

C C is a ring of brass or other suitable metal for the casing in itsfront.

D D is the graduated ring or dial plate.

E is a glass front.

F is a disk of steel as a manometer spring to sustain and indicate thepressure of steam.

G is a lining of india rubber to protect the steel disk from the steamand to furnish a bed or packing where it is in contact with the ledge aand covering the steam chamber H.

I is a stud of hardened steel fixed firmly to the disk.

J is an arm holding a sector K, at its center of motion 1), at theelbow, and the pinion L on the hub-of which the index 0 is placed at thewrist, of the said arm. The sector and pinion are shown .in proper viewand not in section.

M is a steam passage or port, to admit steam to the chamber The diskplate F is composed of sheet steel in a circular form and having itsedge turned or raised as shown at e, by being forced into or throughdies or otherwise. This edge is then turned in a lathe, so as to beperfectly true or circular, and a corresponding groove is then turned inthe ring B, in which this is fitted accurately and ground in with emery,so as to form a perfectly fitting joint, after being tempered very hard,so as not to suflerit to contract in dimensions by pressure so as tobecome set or changed .in its elasticity by swelling it permanently inthe center, as might be done if its circumference could be at the sametime reduced.

The sector K consists of brass with a segment 9 of side gear, which actsin the pinion L. This sector is suspended at the center pin 7), andrests or bears by its lip a on the stud I. The face of contact of thesector with the stud is of hardened steel, and is radial relative to thecenter of motion 6. The gravity of the sector always tends to keep it incontact with the stud 1. Hence it will be seen that whenever the diskplate F is forced outward by the pressure ofsteam in the chamber H, thestud I attached thereto acts on the sector, and elevates the linb whichturns the pinion and index; and this action is proportional to thedeviation of the face of the disk from its normal state. Butsince thedisk does not yield equally in proportion to the different degrees ofpressure, but requires a greater amount of additional pressure toproduce any specific movement of the disk and index as the pressure isincreased, and also as the angle of contact of the radial steel face ofthe sector, with the stud I varies with the swelling of the disk bypressure, so that the rotary movement imparted to the sector and thenceto the index is not uniform for specific degrees of the prolation, ofthe disk, or of the pressure, the face would require to be graduatedwith constantly decreasing divisions as the pressure is increased, andthe face of each gage can be graduated only by experiment or by trialcomparing it with some other properly graduated gage, at all thedifferent states of pressure. But to compensate for the decreasingspecific action under increased pressure and in order to make thegraduated divisions on the dial plate nearly uniform I so curve the endof the stud I as to act on the radial steel face in contact therewith onthe sector that it shall change its points of contact successively bychange of pressure and position, and act thereon at differentradialdistances from the center of motion Z), of the sector. This curve may beformed experimentally or by trial, and when once formed will serve as amodel for others of the same construction, but each gage to insureaccuracy should be graduated separately and by trial, in connection witha properly graduated standard.

- The disk plate or spring as above described consists of a plainsurface with a raised edge; but it may have circular corrugations aboutits center if preferred; but I prefer a plain disk fitted as describedespecially when extreme pressure is to be applied; for when the flange 6of the disk is accurately and firmly fitted in a groove in the cast ironring I), it can not contract by central pressure and prolation of thedisk, but if held only by screws to the bed in the usual way, withoutrim 0, it might do so, and become set or changed; and a corrugated diskwould yield more readily to extreme pressure, and by its freedom ofaction might for the same reason become changed in its elasticcharacter, by extreme pressure.

I am aware that steam gages have been constructed with disks both plainand corrugated, for monometer springs; and that such have been made toact through the medium of gears, on an index, to exhibit the degree ofpressure sustained by the disk; but such disks have in all cases beenmade without a flange or rim 0, and have always been held in their bedby screws or have been clasped between the case A and ring B, so as tobe susceptible of possible contraction by pres sure on the face of thedisk; and for this cause they often become strained or set, so as not toreturn fully to their original state when free from pressure.

When the monometer spring or disk has heretofore been made to act ongears by contact, as by the action of the stud I, on the sector K, thecont-act has been effected and secured by a spring acting on the gear;or a lever or arm connected therewith; so that when moved or carriedforward by the pressure, and yielding of the monometer spring, the indexwould return to zero and the gear would return to its original positionon the removal of pressure, by the action of the said spring. But in thepresent case this action is effected by the gravity of the sector alone.

Having thus fully described my invention, I wish it to be understoodthat I do not claim an elastic disk for actuating the gearing whichgives motion to the pointer. Neither do I claim a sector for actuatingthe pointer except it be arranged to return to its original position byits own gravity without the aid of a spring, but

hat I do claim as my invention and desire to secure by Letters Patent,is-

The arrangement of the sector with teeth on its side face and radialbearing projection near its axis, on an axis which is at right angles tothe shaft of the pointer pinion and in proper relation for unitedaction, to said pinion and to a controlling stud which terminates in aneccentric curve, substantially as and for the purposes herein specified.

HENRY BATES.

itnesses N. SoHoLr-IELn, H. M. SoHoLrInLn.

